Re: [BUG?]Set XIP mount option on ext2 bypass check.

[Carsten Otte <cotte@de.ibm.com>]

This is an updated version of my bugfix patch. Yan Zheng pointed out,
that ext2_remount lacks checking if -o xip should be enabled or not.
This patch checks for presence of direct_access on the backing block
device and if the blocksize meets the requirements.
Andrew, please consider adding this patch to -mm.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
---
Index: linux-2.6.22-rc4-mm/fs/ext2/super.c
===================================================================
--- linux-2.6.22-rc4-mm.orig/fs/ext2/super.c
+++ linux-2.6.22-rc4-mm/fs/ext2/super.c
@@ -1071,6 +1071,14 @@ static int ext2_remount (struct super_bl
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 		((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
 
+	ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
+				    EXT2_MOUNT_XIP if not */
+
+	if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
+		printk("XIP: Unsupported blocksize\n");
+		goto restore_opts; 
+	}
+
 	es = sbi->s_es;
 	if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
 	    (old_mount_opt & EXT2_MOUNT_XIP)) &&